Suction gripper debris filter

ABSTRACT

In one embodiment, a material sorting system comprises: a suction gripper assembly, the suction gripper comprising: a body assembly that includes: an internal airflow passage configured to communicate an airflow between an airflow application port positioned at a first end of the body assembly and a gripping port positioned at the opposing second end of the body assembly; a cup fitting attached to the gripping port; a suction cup secured to the cup fitting; an attachable filer inserted into the suction cup and fastened to the cup fitting; and a mounting assembly, wherein the mounting assembly includes one or more mounting points for pivotally attaching the suction gripper assembly to a sorting robot of the material sorting system.

CROSS-REFERENCE TO RELATED APPLICATIONS

This patent application is a continuation of U.S. patent applicationSer. No. 16/536,736, entitled SUCTION GRIPPER DEBRIS FILTER filed Aug.9, 2019, which is a U.S. Patent Application claiming priority to, andthe benefit of, U.S. Provisional Patent Application No. 62/718,150,titled “SUCTION GRIPPER DEBRIS FILTER” filed Aug. 13, 2018, each ofwhich is incorporated herein by reference in its entirety.

BACKGROUND

Suction grippers are mechanisms used to pick up and move objects byapplying a concentrated vacuum to portion of an object's surface withsufficient vacuumed strength to hold the object to the gripper. Suctiongrippers thus have some distinct advantages over mechanical grippers.For example, a suction gripper mechanism may be implemented with fewermechanical parts that are subject to wear, malfunction or otherwiserequire maintenance. Suction grippers, however, face challengesoperating in environments, such as recycling and consumer waste handlingfacilities, where the atmosphere is high in dust or other particulates,and where the target object that needs to be captured is not clean. Insuch a dusty high particulate environment with flexible objects, such asplastic bags, the accumulation of contaminants can be expected toeventually fowl the internal of the vacuum motor. While inline filtersmay be installed, these filters often quickly and frequently clog withdust due to operating in the dusty high particulate environment, whichwill limit the force of the vacuum available for a the suction gripperto secure a target object. The frequent maintenance needed to clear orreplace particulate clogged inline filters results in significantdowntime of the system. For the reasons stated above and for otherreasons stated below which will become apparent to those skilled in theart upon reading and understanding the specification, there is a need inthe art for an improved suction gripper debris filter.

SUMMARY

In one embodiment, a material sorting system comprises: a suctiongripper assembly, the suction gripper comprising: a body assembly thatincludes: an internal airflow passage configured to communicate anairflow between an airflow application port positioned at a first end ofthe body assembly and a gripping port positioned at the opposing secondend of the body assembly; a cup fitting attached to the gripping port; asuction cup secured to the cup fitting; an attachable filer insertedinto the suction cup and fastened to the cup fitting; and a mountingassembly, wherein the mounting assembly includes one or more mountingpoints for pivotally attaching the suction gripper assembly to a sortingrobot of the material sorting system.

DRAWINGS

Embodiments of the present disclosure can be more easily understood andfurther advantages and uses thereof more readily apparent, whenconsidered in view of the description of the preferred embodiments andthe following figures in which:

FIG. 1 is a diagram illustrating a robotic vacuum sorting system 10 ofone embodiment of the present disclosure;

FIG. 2 illustrates a suction gripper device of one embodiment of thepresent disclosure;

FIG. 2A illustrates a suction cup assembly of one embodiment of thepresent disclosure;

FIG. 2B illustrates a suction cup assembly in combination with a vacuumsystem of one embodiment of the present disclosure;

FIG. 2C illustrates a suction cup assembly in combination with a suctiongripper of one embodiment of the present disclosure; and

FIG. 3A, 3B and 3C illustrate top, side, and isometric views of anattachable filter for use with a suction cup of one embodiment of thepresent disclosure.

FIG. 4 is a flow chart illustrating a method 300 for one embodiment ofthe present disclosure.

In accordance with common practice, the various described features arenot drawn to scale but are drawn to emphasize features relevant to thepresent disclosure. Reference characters denote like elements throughoutfigures and text.

DETAILED DESCRIPTION

In the following detailed description, reference is made to theaccompanying drawings that form a part hereof, and in which is shown byway of specific illustrative embodiments in which the embodiments may bepracticed. These embodiments are described in sufficient detail toenable those skilled in the art to practice the embodiments, and it isto be understood that other embodiments may be utilized and thatlogical, mechanical and electrical changes may be made without departingfrom the scope of the present disclosure. The following detaileddescription is, therefore, not to be taken in a limiting sense.

FIG. 1 is a diagram illustrating a robotic vacuum sorting system 10 ofone embodiment of the present disclosure. As shown in FIG. 1, a suctiongripper 20 is pivotally mounted to one or more arms of a sorting robot150. System 10 supplies airflow to the suction gripper 20 via vacuumsystem 140. In some embodiments, the vacuum system 140 may be furtherpneumatically coupled to an air source 145, which may comprise a blower,an air compressor, a compressed air storage tank, or some combinationthereof. Although this disclosure may refer to “air” with regards to“airflow”, “air compressor” and other elements, it should be understoodthat the term “air” is used in a generic sense to refer to anycompressible gas or minute of gasses. The sorting robot 150 and vacuumsystem 140 are coupled to and controlled by robot control logic andelectronics 160. Robot control logic and electronics 160 may comprise orotherwise be implemented with one or more processors coupled to a memoryand programmed to execute code to implement the function attributed torobot control logic and electronics 160 described herein. As such, tocommunicate control signals, robot control logic and electronics 160 mayfurther comprise elements to generate electrical and/or controlpneumatic signals to the sorting robot 150 and vacuum system 140. Insome implementations, robotic vacuum sorting system 10 further comprisesat least one imaging device 162 (which may comprise, for example, aninfrared camera, visual spectrum camera, or a some combination thereof)directed at a conveyer belt 50 that transports target objects (shown at55) within the operating reach of the robotic vacuum sorting system 10.The imaging device produces an image signal that is delivered to therobot control logic and electronics 160 and which may be used by robotcontrol logic and electronics 160 to send control signals to the sortingrobot 150 to position the suction gripper 20, and send airflow controlsignals to the vacuum system 140, in order to initiate a capture action.In some embodiments, the robotic vacuum sorting system 10 may alsocomprise a pressure sensor 143 providing a signal to the robot controllogic and electronics 160 so that a vacuum is successfully achieved. Foradditional details of robotic vacuum sorting system 10 which may be usedin combination with the embodiments described herein, see U.S.Provisional Patent Application 62/561,400 titled “Systems and Methodsfor Robotic Suction Grippers” filed on Sep. 21, 2017, which isincorporated herein by reference in its entirety,

Embodiments of the present disclosure provide for an attachable filterto block obstructions from entering a suction-based piping systems, suchas the vacuum system 140 of the robotic vacuum sorting system 10 shownin FIG. 1. As discussed below, the attachable filter embodimentsdescribed herein provide the ability to avoid blockages causes by largeobjects, plastic sheets and/or bags and the like, demonstrate anextended period of operation before filters need to be cleaned orreplaced due to particulate (i.e. dust) accumulation, and can producevolumetric flow rate improvements through the bellowed suction gripperassembly 20 over prior designs, including a design using no filter atall. As illustrated below, in some embodiments, the attachable filterdisclosed here comprise a porous apparatus (that is, a device havingmany apertures or holes that permit air to flow through the device) thatattaches to the inlet of a vacuum piping system, such as for a roboticsuction gripper. The holes allow air and small partials, such as dust,to enter the piping system, while blocking out large objects, such asplastic bags.

FIG. 2 is a diagram illustrating a suction gripper mechanism 20 (alsoreferred to herein as “suction gripper 20” or “suction gripper assembly20”) of one embodiment of the present disclosure such as described withrespect to FIG. 1. In some embodiments, the gripper assembly 20comprises a body assembly 202 and a mounting assembly 203. In theembodiment shown in FIG. 2, body assembly 202 houses a linear bearingcomponent 209, and mounting assembly 203 is rigidly secured around thebody assembly 202. In one embodiment, the mounting assembly 203comprises a ring shaped assembly having a through hole through which thelinear bearing component 209 is positioned and securely attached. Insome embodiments, the mounting assembly 203 and the body assembly 202may be rigidly coupled together such as through a weld or mechanicalfastener. In some embodiments, the mounting assembly 203 and bodyassembly 202 may comprise a single integrated part. The mountingassembly 203 further comprises one or more mounting points 204 via whichthe mounting assembly 203 can be pivotally coupled to the sorting robot150.

In the embodiment of FIG. 2, the suction gripper assembly 20 furthercomprises a linear shaft element 201 secured within the linear bearing209 and having a freedom to travel axially up and down with respect tothe axis of the linear bearing 209. The linear shaft 201 comprises aninternal airflow passage 220 configured to communicate an airflow(having either a positive or negative air presser) between an airflowapplication port 207 positioned at a first end of the linear shaft 201and a gripping port 206 positioned at the opposing second end of thelinear shaft 201. The suction cup assembly 100 may comprise a flexible,bellowed suction cup element 120 (which may be a rubber, latex, or otherflexible material) and removable coupler, or cup fitting 130, which maybe attached to the linear shaft element 201 and define the opening ofthe gripping port 206. In some embodiments, the linear shaft 201 may befree to travel axially up and down within a linear bearing 209. A springmechanism 205 is positioned between the mounting assembly 203 and a stopdevice 212 located near the distal second end of the linear shaft 212proximate to the gripper port 206, to hold the linear shaft 201 in afully extended position when the suction gripper 100 is not holding atarget object 55.

FIG. 2A is an exploded view diagram illustrating an example attachablefilter 110 in combination with a bellowed suction cup 120. In thisembodiment, the attachable filter 110 is positioned within the suctioncup 120 and fastened to the cup fitting 130 from within the suction cup120. The cup fitting 130, in turn, mounts the components of the suctioncup assembly 100 to linear shaft element 201 of the gripper assembly 20.As shown in FIG. 2A, the attachable filter 110 may be rigidly fastenedto the cup fitting 130 by a threaded connection. In other embodiments,other fastening mechanisms, such as but not limited to a twist cam orset screws, may be used. The cup fitting 130 may be secured to thegripper assembly 20 by set screws, clamps, threads, or other fasteningmechanisms 131. Having a rigidly attached attachable filter 110, asopposed to a press-fitted filter, can be beneficial in many application,including recycling robotics, where a dislodged filter may causemechanical jams within the gripper assembly 20 or other undesiredeffects. A filter at the pipe inlet to the gripper assembly 20 andvacuum system 140, as opposed to somewhere along the piping system, isalso beneficial in blocking obstructions from entering the piping systemall together.

Referring to FIG. 2B, in some embodiments, the vacuum system 140comprises a vacuum generator 342 coupled to the airflow port 207 ofsuction gripper 20, and providing an airflow through the internalairflow passage 220 via (for example) air supply tubing 344. In someembodiments, the vacuum generator 342 comprises a compressed air drivenVenturi and/or Coanda type technology vacuum system. That is the motiveforce that pulls a vacuum through supply tubing 344 is a flow of acompressed air stream (for example, supplied by air source 145) thatflows through the vacuum generator 342. Utilization of a Venturi and/orCoanda vacuum generator addresses the problem of pulling dirty (that is,particulate heavy) air into an intake of a vacuum motor. In someembodiments, the vacuum generator 342 is designed such that its vacuumport and exhaust path are placed directly inline (straight through),undisturbed. The utilization of a Venturi and/or Coanda technologyvacuum generator 342 in combination with the suction gripper 20 reducesthe need for particulate filtration because such a vacuum system 140 caninternally separate dust particles from the airflow received from thesuction gripper 20. Dust that is not separated by the vacuum system 140may be conveniently discharged, for example into an optional holdingcontainer, as opposed to being pulled into a vacuum motor.

Accordingly, one objective of the attachable filter 110 is to blocklarge objects 55 from entering the piping of the vacuum system 140through the suction gripper 20. Some objects 55, such as plastic bags orsheets of plastic, may be sucked into piping of the vacuum system 140 byentering through the suction cup 120, and passing through the cupfitting 130. The attachable filter 110 acts as a barrier for such largeobjects, while still allowing air and small, harmless particulates toenter the piping of vacuum system 140.

In some embodiments, the attachable filter 110 may also serve to keepthe suction cup 120 from collapsing on itself. When too much downwardforce is applied to certain suction cups, the bottom skirt 121 of thesuction cup may fold over the bellows 122. As such, in some embodiments,the attachable filter 110 is designed to have a length so that thefilter 110 will at least partially restrict compression of the suctioncup. That is, the attachable filer 110 may collide with the object 50before the cup 120 reaches the critical amount of compression that canlead to collapsing of the bottom skirt.

FIGS. 3A, 3B and 3C illustrate respective top, side and isometric viewsof the attachable filter 110 of one embodiment of the presentdisclosure. The attachable filter 110 comprises a suction applicationsurface 310 that includes a plurality of holes 315 (i.e., the abovementioned pores), and an open port mounting interface 320 that includesfastening features (such a threads for example) compatible withfastening features of the cup fitting 130 for which it can be coupled.The attachable filter 110 is easy to install, compared to other filteralternatives.

The plurality of holes 315 allow air to pass through the Filter 110 andinto the air supply tubing 344 of the vacuum system 150. In someembodiments, the largest outer diameter of the attachable filter 110 maybe slightly smaller than the smallest inner diameter of the suction cup120 into which is it inserted. This means it can fit though the suctioncup 120 with ease. In some embodiments, the attachable filter 110 mayprovide a keyed holed 340 for insertion of a tool used to install orremove the attachable filter 110 from the cup fitting 130. For example,in FIG. 3A, a hexagonal shaped hole 340 at the center of the suctionapplication surface 310 is designed for a standard Allen Key to beinserted, so that the user can easily tighten and torque the attachablefilter 110 (for example, via threads) onto cup fitting 130.

As mentioned above, the plurality of holes 315 may be sized to allowdust and fine particles through the system but prevent materials such aplastic bags and similar objects larger than about ½ inch in diameter.So as to not unnecessarily restrict volumetric flow, the totalcross-sectional area of the holes 315 of the attachable filter 110should be greater than the smallest pipe cross-sectional area (e.g. ofthe internal airflow passage 220), which in the example embodiment ofFIG. 2A would be the opening in the cup fitting 130 for port 206. Thismeans that theoretically, the adaptive filter 110 may only act as aminor loss in the vacuum system 140, and does not significantly decreasethe volumetric flow rate through internal airflow passage 220. Moreover,the plurality of holes 315 are large enough such that they are noteasily clogged by dust sized particulates, but small enough that plasticbag/sheet type objects 50 do not get pulled into the cup fitting 130 orfurther into the suction gripper 20 or air supply tubing 344. The holes315 are not necessarily circular, but may comprise different shapes.Moreover, the holes 315 on any given suction application surface 310need not be uniform in either size or shape, though they may be. In onenon-limiting example embodiment of attachable filter 110, the suctionapplication surface 310 may comprise a plurality of holes 315 that arecircular, or approximately circular, each having a diameter greater thanor equal to 1 millimeter (mm) up to 2 centimeter (cm). In anotherexample embodiment of the of attachable filter 110, the suctionapplication surface 310 may comprise a plurality of holes 315 that maybe generally circular or comprise another geometric shape each having across section area from 1 mm² to 2 cm². Rounded and circular shapedholes 315 in particular contribute to prevent dirt build up over longperiods of time. Such hole sized can be expected, given the typical dustparticulates found in a typical recycling facility, to permit continuousoperation of the gripper assembly 20 for periods of 1 week or morewithout requiring filter change due to particulate clogging, and withoutclogging of the gripper assembly 20 due to inhaling of plastic bags,sheets, or other materials. The attachable filter 110 is thus designedto withstand an extended period of time in dirty environments, withoutneeding to be cleaned. The relatively large holes 315 (which may becombined with other optional features such as rounded fillets and asmooth converging neck) means that dirt and grime will not clog theattachable filter 110. Unlike filters made out of mesh, fibers, or thelike, which may require replacement or cleaning multiple times per day,the attachable filter 110 does not clog the piping system withparticular grime or large plastic material.

Although the attachable filter 110 will prevent the suction system 140from becoming clogged from a large object, a plastic bag or sheet maystill cause a blockage within the bellows 122 of the suction cup 120.For such cases, the vacuum system 140 may be reversed to create apositive flow of air out from the attachable filter 110 to expel theobject. In some embodiments, the robot control logic and electronics 160controls the vacuum system 140 to optionally reverse the airflow throughthe suction gripper 20 to release and/or propel the object from thesuction cup 130. In some embodiments, the airflow may be reversed at thecompletion of each capture action. In other embodiments, the robotcontrol logic and electronics 160 may sense a blockage, for examplebased on an output from the pressure sensor 143 and based on that sensoroutput reverse the airflow to expel the object. In such embodiments,having the attachable filter 110 rigidly fastened to the cup fitting 130(such as described below) may serve to prevent expulsion of theattachable filter during times of reversed airflow operation where airis blown out from the suction gripper 20.

Referring back to FIGS. 3A-3C, between the suction application surface310 and mounting interface 320, the internal airflow passage of theattachable filter 110 comprises angled walls 330 defining within thefilter 110 a partially conical, funnel shaped passage that tapers to asmaller inner diameter from the suction application surface 310 towardsthe mounting interface 320. The funnel shaped passage functions tochannel the airflow seamlessly through the suction cup 120, and directsit to gripping port 206 and into the vacuum system 140. This geometryhas been found by the inventors to not only provide from a greatervolumetric flow rate through the suction gripper 20 as compared to priorfine filters, but also a greater volumetric flow rate through thesuction gripper 20, measured from the bottom of a suction cup, ascompared to a suction gripper 20 having no filter installed at all.

For example, when an airflow is pulled into the suction cup 120 byvacuum system 140, the bellows 122 will generate turbulence due to thesubstantial changes in cross-sectional area, and thus decrease averageflow. In a case with a suction cup 120 that comprises one or more manybellows 122, the geometry of the attachable filter 110 essentiallydecreases the number of area changes inside the suction cup 120 as seenby the fluid flow, thus decreasing the amount of turbulence, andtherefore, increasing average flow. The minor loss introduced byintroducing the adaptive filter 110 is less than the losses due to thechanges in cross-sectional area of the suction cup. In one set ofcontrolled experiments performed by the inventors comprising about 20trials, the flowrate of a suction cup assembly 100 was measured asalternately equipped with no filter, a prior art mesh disk-filter, andwith an attachable filter 110. After completing the experiments, it wasfound that the suction cup assembly 100 when combined with theAttachable Filter allowed the most suction flow to enter the suction cup130, at an average of 29.1 CFM, while the disk-filter only allowed 22.5CFM, and the suction cup 130 without a filter allowed 25.85 CFM ofairflow. Although installing the Attachable Filter 100 in the suctioncup assembly 100 introduces a minor loss, it provides a less interruptedchannel for airflow, which, supported by experimental results, increasesthe average flowrate.

FIG. 4 is a flow chart illustrating a method 400 for one embodiment ofthe present disclosure. It should be understood that the features andelements described herein with respect to the method 400 shown in FIG. 4and the accompanying description may be used in conjunction with, incombination with, or substituted for elements of any of the otherembodiments discussed with respect to the other figures, or elsewhereherein, and vice versa. Further, it should be understood that thefunctions, structures and other description of elements associated withembodiments of FIG. 4 may apply to like named or described elements forany of the other figures and embodiments and vice versa. The method 400begins at 410 with drawing an airflow through a suction gripperassembly, the suction gripper comprising a body assembly and a mountingassembly such as shown in any of the figures and embodiments discussedabove. The body assembly includes: an internal airflow passageconfigured to communicate an airflow between an airflow application portpositioned at a first end of the body assembly and a gripping portpositioned at the opposing second end of the body assembly, a cupfitting attached to the gripping port, a suction cup secured to the cupfitting, and an attachable filer inserted into the suction cup andfastened to the cup fitting; and wherein the mounting assembly includesone or more mounting points for pivotally attaching the suction gripperassembly to a sorting robot of the material sorting system. The methodproceeds to 420 with drawing an airflow through the internal airflowpassage using a vacuum system coupled to the airflow application portand to 430 with utilizing the attachable filter to filter the airflow.

In various alternative embodiments, system elements, method steps, orexamples described throughout this disclosure (such as the sortingrobot, robot control logic & electronics, imaging devices, vacuumsystem, and/or sub-parts of any thereof, for example) may be implementedusing one or more computer systems, field programmable gate arrays(FPGAs), or similar devices and/or comprising a processor coupled to amemory and executing code to realize those elements, processes, steps orexamples, said code stored on a non-transient data storage device.Therefore, other embodiments of the present disclosure may includeelements comprising program instructions resident on computer readablemedia which when implemented by such computer systems, enable them toimplement the embodiments described herein. As used herein, the term“computer readable media” refers to tangible memory storage deviceshaving non-transient physical forms. Such non-transient physical formsmay include computer memory devices, such as but not limited to punchcards, magnetic disk or tape, any optical data storage system, flashread only memory (ROM), non-volatile ROM, programmable ROM (PROM),erasable-programmable ROM (E-PROM), random access memory (RAM), or anyother form of permanent, semi-permanent, or temporary memory storagesystem or device having a physical, tangible form. Program instructionsinclude, but are not limited to computer-executable instructionsexecuted by computer system processors and hardware descriptionlanguages such as Very High Speed Integrated Circuit (VHSIC) HardwareDescription Language (VHDL).

Although specific embodiments have been illustrated and describedherein, it will be appreciated by those of ordinary skill in the artthat any arrangement, which is calculated to achieve the same purpose,may be substituted for the specific embodiment shown. This applicationis intended to cover any adaptations or variations of the presentedembodiments. Therefore, it is manifestly intended that embodiments belimited only by the claims and the equivalents thereof.

1. (canceled)
 2. A system, the system comprising: a suction gripperassembly comprising: an internal airflow passage configured tocommunicate an airflow between an airflow application port positioned ata first end of the suction gripper assembly and a gripping portpositioned at a second end of the suction gripper assembly; a cupfitting attached to the gripping port; and an attachable filter coupledto the cup fitting.
 3. The system of claim 2, wherein the attachablefilter is coupled to the cup fitting by one or more of the following: athreaded connection, a twist cam, or a set screw.
 4. The system of claim2, wherein the suction gripper assembly further includes a suction cupcoupled to the cup fitting and wherein the suction gripper assembly isinserted into the suction cup.
 5. The system of claim 4, wherein thesuction cup comprises a bellows suction cup.
 6. The system of claim 4,wherein the attachable filter extends from the cup fitting into thesuction cup to at least partially restrict compression of the suctioncup.
 7. The system of claim 2, wherein the attachable filter comprises asuction application surface that includes a plurality of holes.
 8. Thesystem of claim 7, wherein the plurality of holes comprises holes thatare circular or approximately circular.
 9. The system of claim 7,wherein the plurality of holes comprises rounded fillets.
 10. The systemof claim 7, wherein each of at least some of the plurality of holes hasa diameter greater than or equal to 1 millimeter up to 2 centimeters.11. The system of claim 7, wherein each of at least some of theplurality of holes has a cross section area from 1 mm² to 2 cm².
 12. Thesystem of claim 7, wherein the attachable filter comprises a conicalshape converging from the suction application surface towards the cupfitting.
 13. The system of claim 2, wherein the attachable filtercomprises a hole that is configured to a receive a tool, wherein thetool is configured to either install the attachable filter or remove theattachable filter.
 14. The system of claim 2, wherein the suctiongripper assembly is coupled to a sorting robot, wherein the sortingrobot is configured to position the suction gripper assembly.
 15. Thesystem of claim 2, further comprises a vacuum generator, wherein thevacuum generator is coupled to the airflow application port of thesuction gripper assembly.
 16. The system of claim 15, wherein the vacuumgenerator comprises a compressed air drive Venturi or Coanda vacuumsystem.
 17. The system of claim 2, further comprising: a vacuum systemcoupled to the airflow application port of the suction gripper assembly;and a pressure sensor; and wherein the vacuum system is configured toreverse airflow direction through the internal airflow passage inresponse to an output from the pressure sensor.
 18. A method,comprising: drawing an airflow through a suction gripper assembly,wherein the suction gripper assembly includes: an internal airflowpassage configured to communicate the airflow between an airflowapplication port positioned at a first end of the suction gripperassembly and a gripping port positioned at a second end of the suctiongripper assembly, a cup fitting attached to the gripping port, and anattachable filter coupled to the cup fitting; and using the attachablefilter to filter the airflow.
 19. The method of claim 18, wherein thesuction gripper assembly further includes a suction cup coupled to thecup fitting and wherein the suction gripper assembly is inserted intothe suction cup.
 20. The method of claim 19, wherein the suction cupcomprises a bellows suction cup.
 21. The method of claim 18, wherein theattachable filter comprises a conical shape converging from a suctionapplication surface towards the cup fitting.